A federal judge has blocked Aetna’s proposed $37 billion takeover of Humana, calling it anticompetitive. The merger would have created an industry-changing health insurance colossus at a time when the industry’s regulatory future is uncertain. Aetna already pulled out of most Obamacare exchanges this year, following through on a threat it made to the DOJ, which has thwarted a number of mega mergers over the last few years. Read more from Bloomberg.CZ